Why is a6 in Ruy Lopez?

Answered by Douglas Hiatt

The move a6 in the Ruy Lopez opening serves several important purposes. Firstly, it helps to control the b5 square, preventing White from establishing a strong presence there with their bishop. This is crucial because the b5 square is on the a4 to e8 diagonal, which is a key diagonal for both bishops. By playing a6, Black “puts the question” to the White bishop, forcing it to make a decision on whether to capture the knight on c6 or retreat.

If White chooses to immediately capture the knight on c6 with their bishop (Bb5xc6), Black can respond by playing b7 to b5, kicking the White bishop away from the a4 to e8 diagonal. This move not only relieves the pressure on the c6 pawn but also allows Black to potentially develop their pieces more harmoniously. Moreover, by playing b5, Black gains more control over the center and creates a potential outpost for their knight on b4.

On the other hand, if White does not capture the knight on c6 immediately, Black can delay playing b5 and focus on developing their other pieces. This flexibility allows Black to adapt their strategy based on White’s moves, making a6 a versatile and useful move in the Ruy Lopez.

In my personal experiences, I have found that playing a6 in the Ruy Lopez can often lead to interesting and dynamic positions. It creates a tactical and strategic imbalance, forcing both players to carefully consider their next moves. This move has been employed by many strong players throughout history, including famous games played by World Champions such as Anatoly Karpov and Garry Kasparov.

To summarize, a6 in the Ruy Lopez is a valuable move because it puts the question to the White bishop and allows Black to control the b5 square. It offers flexibility in the development of Black’s other pieces and can lead to dynamic positions. Its usage has been demonstrated by strong players and has stood the test of time in chess history.